Experimental Investigation on Super High Viscosity Oil-Water Two-Phase Flow in a Horizontal Pipe

Document Type : Research Article


Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, I.R. IRAN


The flow patterns and pressure gradient of a two-phase mixture of water/super high viscous oil in a horizontal pipe were experimentally investigated. The mixture containing oil with a viscosity of 67 cP and density of 0.872 g/cm3, and pure water flows through an acrylic pipe with a length of 6m and a diameter of 20 mm. Superficial velocities of water and oil were in the range between 0.18–1.2 m/s and 0.18–0.95 m/s, respectively. Six flow patterns were identified. The stratified flow became visible at low velocities of oil (<0.42 m/s) and water (<0.26 m/s) and bubbly flow patterns happened at low superficial oil velocities (Uso = 0.18–0.22 m/s). The dispersion of oil in water (DO/W) occurred at high superficial water velocity (Usw =0.79 – 1.2 m/s) at low or moderate superficial oil velocities (Uso = 0.18 –0.53 m/s). Dispersion of water in oil (DW/O) appeared from superficial oil velocity of higher than 0.69 m/s. The effect of oil viscosity on flow structure was assessed by comparing the present work with the available data and this revealed that the extent of dual continuous patterns reported by other systems containing low viscosity oil is 5% higher than the results of the present study. The effect of oil viscosity on the pressure gradient was also investigated. The pressure gradient values obtained in this study were 80% greater than other studies at similar superficial oil and water velocities. The experimental pressure gradient was also compared with the values predicted by the Al-Wahaibi correlation and two-fluid model. The Al-Wahaibi correlation agreed reasonably with the experimental results, with an average absolute error of less than 9%, while
 the error of the two-fluid model was 30%.  Based on the results, a clear overview of the flow patterns and pressure drop with detailed information was presented.


[1] Kong R., Kim S., Characterization of Horizontal Air-Water Two-Phase Flow, Nucl. Eng. Des., 312: 266-276(2017).
[2] Angeli P., Hewitt G.F., Pressure Gradient in Horizontal Liquid-Liquid Flows, Int. J. Multiphase Flow,24(7): 1183–1203(1998).
[3] Angeli P., Hewitt G.F., Flow Structure in Horizontal Oil-Water Flow, Int. J. Multiphase Flow, 26(7): 1117–1140 (2000).
[4] Oddie G., Shi H., Durlofsky L.J., Aziz K., Pfeffer B., Holmes J.A., Experimental Study of Two and Three Phase Flows in Large Diameter Inclined Pipes, Int. J. Multiphase Flow, 29(4): 527–558 (2003).
[5] Rodriguez O.M.H., Oliemans R.V.A., Experimental Study on Oil-Water Flow In Horizontal and Slightly Inclined Pipes, Int. J. Multiphase Flow, 32(3): 323–343 (2006).
[6] Mandal T.K., Chakrabarti D.P., Das G., Oil Water Flow Through Different Diameter Pipes–Similarities and Differences, Trans. IChem E. Part A. Chem. Eng. Res. Des, 85(8): 1123–1128 (2007).
[7] Xu X., Study on Oil-Water Two-Phase Flow in Horizontal Pipelines, J. Pet. Sci. Eng, 59(1): 43-58 (2007).
 [8] Bannwart A.C., Rodriguez O.M.H., Trevisan F.E., Vieira F.F.,de Carvalho C.H.M., Experimental Investigation on Liquid–Liquid–Gas Flow: Flow Patterns and Pressure-Gradient, J. Pet. Sci. Eng., 65(1-2): 1–13(2009).
[9] Hanafizadeh P., Ghanbarzadeh S., Saidi M., Visual Technique For Detection of Gas-Liquid Two-Phase Flow  Regime in the Airlift Pump, J. Pet. Sci.  Eng., 75(3-4): 327–335 (2011).  
[10] Hanafizadeh P., Hojati A., Karimi A.,  Experimental Investigation of Oil- Water Two   Phase Flow Regime in an Inclined Pipe, J. Pet. Sci. Eng., 136: 12-22 (2015).
[13] Zhuoran D., ZijiangY., Xiaohong Y., Mamoru I., Experimental Study on Void Fraction, Pressure Drop and Flow Regime Analysis in a Large ID Piping System, Int. J. Multiphas. Flow, 111: 31-419 (2019).
[14] Azizi S., Karimi H., Darvishi P., Flow Pattern and Oil Holdup Prediction in Vertical Oil-Water Two-Phase Flow Using Pressure   Fluctuation Signal, Iran. J. Chem. Chem. Eng. (IJCCE), 36(2): 125–141(2017).
[15] Ganat T., Ridha S., Hairir M., Arisa J., Gholami R., Experimental Investigation of High‑Viscosity Oil-Water Flow in Vertical Pipes: Flow Patterns and Pressure Gradient, J. Petrol. Explor. Prod. Technol, 9: 2911–2918 (2019).
[16] Zhai L., Liu R., Zhang H., Jin N., Complex Admittance Detection of Horizontal Oil-Water Two-Phase Flows Using a Capacitance Sensor, IEEE Sensors Journal, 19(17): 7489-7498 (2019).
[17] Zhai L., Liu R., Zhang H., Jin N., Prediction of Pressure Drop for Segregated Oil-Water Flows in Small Diameter Pipe Using Modified Two-Fluid Model, Exp. Therm. Fluid Sci,114:110078 (2020).
[18] Jing J., Yin X., Mastobaev B., Valeev A., Sun J., Wang S., Liu H., Zhuang L., Experimental Study on Highly Viscous Oil-Water Annular Flow in a Horizontal Pipe with 90° Elbow, Int. J. Multiph. Flow, 135: 103499 (2021).
[19] Ahmad S., Ashraf M., Ali K., Numerical Simulation of Viscous Dissipation in a Micropolar Fluid Flow through a Porous Medium, J. Appl. Mech. Tech. Phy., 60: 996-1004 (2019).
[20] Hasanzadeh Y., Alavifazel S.A., Azizi Z., Peyghambarzadeh S.M., Azimi A., Prediction of the Pressure Drop in Water-High Viscosity Oil Flows Using Artificial Neural Network, Solid State Technology, 64(2): 7167-7186 (2021).
[21] Valle A., Kvandal H., Pressure Drop and Dispersion Characteristics of Separated Oil/Water Flow, Two-Phase Flow Modelling and Experimentation, Int. Symposium, 1: 583–592 (1995).
[22] Yusuf N., Effect of Oil Viscosity on the Flow Structure and Pressure Gradient in Horizontal Oil-Water Flow, Chem. Eng. Res. Des., 90(8): 1019–1030 (2012).
[23] Chakrabarti D.P., Das G., Ray S., Pressure Drop in Liquid-Liquid Two Phase Horizontal Flow: Experiments and Prediction, Chem. Eng. Technol., 28: 1003–1009 (2005).
[24] Al-Wahaibi T., Pressure Gradient Correlation for Oil–Water Separated Flow in Horizontal Pipes, Exp. Therm. Fluid Sci., 42: 196–203(2012).
[25] Hasanzadeh Y., Alavifazel S.A., Azizi Z., Peyghambarzadeh S.M., Azimi A., Development of A New Correlation for Estimating Pressure Gradient of Oil- Water Two Phase Flow in a Horizontal Pipe, Int. J. ADMT, 14(4): 51-58 (2021).